APOE and Alzheimer disease: While altered lipid metabolism is reported here, the degu Apoe Mt4 variants may also contribute to AD-like phenotypes via other functions of APOE known to be relevant to AD pathogenesis, including brain glucose metabolism and the trafficking of Aβ, considering that this animal model has been reported as a natural model of atherosclerosis, diabetes and the neuropathogenesis of AD (Homan et al., 2010; Hurley et al., 2018).